The present invention generally relates to an electrical connecting mechanism for a semiconductor device and other electrical elements and more particularly to a connecting device for electrical connection to an IC package in which many pins are arranged with a fine pitch, or a high speed, high frequency IC, such as a bare chip, wafer or other electrical element.
A contactor, such as a probe pin, has generally been used as a device for electrical connection to a semiconductor device and other electrical elements, particularly for testing purposes.
FIG. 1 is a diagram showing a structure of a probe pin in the related art. The probe pin shown in FIG. 1 includes a metal tube or pipe 200, a coil-shape spring 201, a metal end piece 202 and a terminal portion 203. The coil-shape spring 201 is provided within the metal pipe 200 and the metal end piece 202 is spring-biased in the upward direction of the drawing by the spring force of the coil-shape spring 201. The metal end piece 202 is provided to establish an electrical connection with an external electrode of a semiconductor device as the object of the test and the spring force produces a contact pressure between the metal end piece 202 and the external electrode. The terminal portion 203 is connected to testing equipment for testing the semiconductor device.
In the probe pin shown in FIG. 1, when the metal end piece 202 is in contact with an external electrode of the semiconductor device, a current flows to the terminal portion 203 via the metal tube or pipe 200 from the metal end piece 202. Therefore, the probe pin itself must be formed in a fine structure in order to provide many of these pins arranged to correspond with an IC package with many external electrodes arranged in a fine pitch. However, since the probe pin has a comparatively complicated structure, it is difficult to manufacture a fine probe pin. Moreover, even if such a fine probe is formed, it becomes very expensive.
Therefore, a probe pin as shown in FIG. 2 tends to be used recently. The probe pin of FIG. 2 includes a guide plate 210, a plurality of holes 211 provided in the guide plate 210 and a plurality of coil-shape springs 212 inserted into the holes 211. One end of the coil-shape spring 212 to be used as a contactor is placed in contact with an external electrode of a semiconductor device, while the other end of the spring 212 is connected to a testing apparatus. This type of probe pin is formed in a simplified structure and therefore many coil-shape springs 212 can be arranged with a fine pitch.
In the probe pin having the structure shown in FIG. 2, a current is transferred via the coil-shape spring 212. If a certain turn of the coil-shape spring 212 is not kept in contact with the next single turn, a current is transferred through a spiral path of metal wire of the coil-shape spring. Therefore, a problem arises that resistance and inductance become large.
In the case of the structure of the probe pin shown in FIG. 2 where a certain turn of the coil-shape spring 212 is in contact with the next single turn in many areas, resistance and inductance can be lowered. However, in this case, when the coil-shape spring 212 is compressed by a contact pressure from the external electrode, the contact condition of a certain turn and the next single turn changes, thereby resulting in a delicate change of a current transfer route. Therefore, a problem arises that fluctuation is generated in the current transfer characteristic in the contact condition.